Dissecting the complications of catheter‐based aortic valve implantation: Aortic tears may occur

Aortic valve stenosis is known to be a lethal disease, whose malignant natural course can be reverted by cardiac surgery. However, in practice, the surgical treatment is not applicable for a large group of patients, either due to patients' refusal or because of a too high-operative risk. Thus far, with no other therapeutic options, patients with severe aortic stenosis who are left untreated present a 75% mortality rate after 3 years [1]. Although only recently introduced, and still restricted to some countries for routine use, the new transcatheter aortic valve implantation (TAVI) procedure has been perceived by many as a valid treatment choice for inoperable patients with aortic stenosis. In this issue of CCI, Gerber and coworkers describe a major complication after catheter-based aortic valve implantation: aortic dissection. They report on two cases that presented aortic dissection followed by cardiac tamponade and death only a few days after the index procedure. The authors pointed out that the unfavorable outcome of their patients could have been adversely influenced by the use of double anti-platelet medications. Of note, such therapeutic scheme is currently prescribed as part of the default post-TAVI management on an empirical basis, with no formal study to evaluate its clinical utility. Also, the authors questioned whether the balloon dilatation may have predisposed to aortic dissection. However, TAVI without valve predilatation is currently not performed and, therefore, cannot be counted on as a strategy to minimize the risk of aortic wall damage. Curiously, both cases occurred after the implantation of a balloon-expandable Edwards-Sapien valve. It is not known whether aortic dissection can also be expected as a complication for patients treated with the Corevalve system, which is self-expandable and has a longer length of the metallic stent protruding into the ascending aorta. Transcatheter aortic valve treatment is still in its early days. The article of Gerber et al. reflects the above. The authors describe a serious complication, for which little insight is given on its mechanisms, and no hint is provided about its frequency, risk factors, or potential means to avoid it. Although potentially revolutionary, in many ways, TAVI is still an experimental strategy. Most of the clinical information on its strengths and limitations is yet to be constructed. To list only a few issues, important questions remain open regarding the best access route, the durability of the prosthesis, the clinical impact of cerebral and systemic emboli, the effect of paravalvar regurgitation, and the consequences and best management of prosthetic endocarditis. Even the need for permanent pacemaker, a common post-TAVI event, persists disturbingly unpredictable, with, so far, virtually no description of a strategy to reduce its risk. Due to its remarkable clinical results in high-risk patients, most certainly TAVI will be proposed as a potential alternative also for good surgical candidates. However, differently from the current last-resource context, where TAVI can almost intuitively be legitimated as an option, the threshold to adopt the new technique to less sick patients will have to be set at much higher levels, balancing its performance against well established cardiac surgery.